Building diary

Address: Spechtweg 40, 70499 Stuttgart, Germany

Building owner: City of Stuttgart

Degree Days: 3555 Kd (basis for calculation 15 °C)


Building type and size:

The Solitude-Gymnasium is a secondary school with about 690 pupils in 29 classes. The school consists of 4 different buildings:

1: main building from 1975

2: big pavilion from 1966

3: small pavilion from 1971

4: gym from 1975. About 700 m² of the gym were rebuilt in 1991.

In the main building and the gym are flats for the two caretakers. The school has a total floor area of 8924 m², whereof 2038 m² are used for the gymnasium. The school is used by the pupils from 7.30 am until 4.30 pm. The gym is used also in the evening by different sports clubs.


Short description of the renovation and its purpose:

The entire school will be renovated because of structural damages. A holistic approach is intended with an improvement of the energy efficiency and of the indoor climate. The entire building envelope will be insulated and improved. As the boiler of the main building is relatively new (from 2004), it will be kept, but the boiler of the small pavilion and the rest of the heating system will be completely renewed. Also the use of a solar thermal system or a CHP is intended. There’s a ventilation system in a few rooms in the main building and one in the gym which shall be optimized and get a heat recovery.


Energy conservation and renewable energy measures:

  • Energy conservation: high-efficient windows, insulation, exterior sun shades with light-guiding units, high-efficient lighting
  • Efficient energy supply: new heating system for the whole site. Installation of combined heat and power unit or solar thermal. Optimizing of the domestic hot water supply. The existing gas condensing boiler will be kept for peak load.
  • Renewables: solar thermal collectors for domestic hot water, PV, improvement of daylight use, natural night-ventilation
  • Advanced control and monitoring: new control for the heating system, domestic hot water and ventilation. Demand-control of artificial lighting, long-term-monitoring with Stuttgart’s energy control system (SEKS)


Project coordinator for the City of Stuttgart and responsible person for the demonstration project:

Dr. Juergen Goerres, Department of Environment of the City of Stuttgart


Full description of the planned renovation (project proposal)



Solitude Gymnasium, Stuttgart 


Training materials:

3 sets of training material for pupilsteachers and technical service personnel available in German


Other demonstration buildings:

Italy: Tito Maccio Plauto school, Cesena

Denmark: Hedegårdsskolen, Ballerup

Norway: Brandengen skole, Drammen


Additional information